<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../react18/react.development.js"></script>
    <script src="../react18/react-dom.development.js"></script>
    <script src="../react18/babel.min.js"></script>
    <script src="../react18/prop-types.js"></script>
</head>

<body>
    <div id="app"></div>
    <script type="text/babel">
        // porps是用来做父子组件通信的
        // - 在父组件中使用子组件的时候,可以给子组件添加属性
        // - 在子组件中组件实例的props属性上,就能拿到这个属性和值
        class Parent extends React.Component {
            state = {
                car: '奥迪'
            }
            render() {
                const { car } = this.state;
                return (
                    <div>
                        <h1>我是父组件</h1>
                        <p>我开的车是{car}</p>
                        <button onClick={this.changeCarHandle}>股票涨停了,换一辆车</button>
                        <hr />
                        <Child a={1} car={car} />
                    </div>
                )
            }
            changeCarHandle = () => {
                this.setState({ car: '自行车' })
            }
        }
        // function Child(props) {
        //     const {car} = props
        //     return
        //     (
        //     <p>我是儿子组件,我开我老子的车{car}</p>
        //     )
        // }
        function Child (props){
            const {car}= props
            return (
                <p>我是儿子组件,我开我老子的车{car}</p>
            )
        }
        //给Child接受的props进行类型限制
        Child.propTypes= {
            a:propTypes.number.isRequired,
            car:PropTypes.string
        }
        
        const root = ReactDOM.createRoot(document.getElementById('app'));
        root.render(<Parent />)
    </script>
</body>

</html>